Vacuum interrupter chamber and contact arrangement for a vacuum circuit breaker

Abstract

The invention relates to a contact arrangement for a vacuum interrupter chamber ( 1 ), which comprises a pair of inner contact pieces ( 11, 12 ), configured as RMF contact pieces, and a pair of outer contact pieces ( 21, 22 ) which are connected in parallel and are mounted closely adjacent to the inner contact pieces ( 11, 12 ). At least one of the inner contact pieces ( 11, 12 ) is movably mounted. The outer contact pieces ( 21, 22 ) are also configured as RMF contact pieces. During interruption, the resulting electric arc can commutate completely or partially to the pair of outer contact pieces ( 21, 22 ). The inner contact pieces are substantially discoid. Advantageously, the contact pieces ( 11, 12, 21, 22 ) are coaxially positioned in relation to each other. The outer contact pieces ( 21, 22 ) are advantageously pot-shaped or tubular.

1. A contact arrangement for a vacuum interrupter chamber ( 1 ), the contact arrangement comprising:
 a pair of inner contact pieces ( 11 ,  12 ) which are configured as radial magnetic field contact pieces, and 
 a pair of outer contact pieces ( 21 ,  22 ) which are arranged adjacent to the inner contact pieces ( 11 ,  12 ), respectively, and are connected electrically in parallel with them, the outer contact pieces being disposed radially outward from the inner contact pieces, 
 wherein at least one of the inner contact pieces ( 11 ) is mounted such that it can move, 
 wherein the inner contact pieces ( 11 ,  12 ) are substantially disc-shaped, 
 wherein the outer contact pieces ( 21 ,  22 ) are-configured as radial magnetic field contact pieces, 
 wherein the inner contact pieces ( 11 ,  12 ) and the outer contact pieces ( 21 ,  22 ) are arranged and designed in such a manner that an arc which is struck during a disconnection process between the inner contact pieces ( 11 ,  12 ) can be commutated entirely or partially between the outer contact pieces ( 21 ,  22 ), and 
 wherein one of the inner contact pieces has a coating thereon and is configured so as to extend beyond its associated outer contact piece in an axial direction by a thickness of the coating; and 
 wherein the other one of the inner contact pieces is configured so as to be disposed flush with its associated outer contact piece in an axial direction. 
 
     
     
       2. The contact arrangement as claimed in  claim 1 , wherein the inner contact pieces ( 11 ,  12 ) and the outer contact pieces ( 21 ,  22 ) are arranged coaxially with respect to one another. 
     
     
       3. The contact arrangement as claimed in  claim 1 , wherein the outer contact pieces ( 21 ,  22 ) are pot-shaped. 
     
     
       4. The contact arrangement as claimed in  claim 1 , wherein each inner contact piece ( 11 ;  12 ) is arranged within its associated outer contact piece ( 21 ;  22 ). 
     
     
       5. The contact arrangement as claimed in  claim 1 , wherein one of the inner contact pieces ( 12 ) is attached to a stationary contact stalk ( 42 ). 
     
     
       6. The contact arrangement as claimed in  claim 1 , wherein at least one of the outer contact pieces ( 21 ) is mounted such that it can move. 
     
     
       7. The contact arrangement as claimed in  claim 1 , wherein the inner contact pieces ( 11 ,  12 ) and/or the outer contact pieces ( 21 ,  22 ) are provided with radially and axially running slots ( 26 ) in order to produce a radial magnetic field when a current flows through the inner contact pieces ( 11 ,  12 ) and/or through the outer contact pieces ( 21 ,  22 ). 
     
     
       8. The contact arrangement as claimed in  claim 7 , wherein the two outer contact pieces ( 21 ,  22 ) are provided with a coating ( 24 ) composed of erosion-resistant material, with the coating ( 24 ) having no slots. 
     
     
       9. A vacuum interrupter chamber ( 1 ;  1 ′) which contains a contact arrangement as claimed in  claim 1 . 
     
     
       10. A switching device, comprising at least one vacuum interrupter chamber ( 1 ;  1 ′) as claimed in  claim 9 . 
     
     
       11. The contact arrangement as claimed in  claim 1 , wherein the movable one of the inner contact pieces is configured so as to extend beyond its associated outer contact piece in an axial direction by the thickness of the coating.